Webster's Revised Unabridged Dictionary · 1913

Obtest

Obtest , transitive verb

[Latin obtestari; ob (see Ob-) + testari to witness, from testis a witness.]

1.
To call to witness; to invoke as a witness. [Rare] — Dryden
2.
To beseech; to supplicate; to beg for. [Rare]

Obtest , intransitive verb

To protest. [Rare] — E. Waterhouse